When does microevolution turn into macroevolution?

I'm still being confused by the word micro-evolution. Is it really something that can be defined? If you think so please answer these.What things would one consider micro- and what macroevolution?
* From warm- to coldblooded animal
* Extra internal organs. A new pair of lungs, heart etc.
* Extra external organs. More fingers, eyes etc.
* New internal/external organs. A tail, fin, lungs that previously breath land/underwater now breath underwater/land etc.
* Enhanced abilities. Better hearing, seeing, stamina, resistance for diseases etc.
* If these enhanced abilities now use different mechanisms to work is it macro or microevolution?Or does micro/macroevolution have more to do with looks?Also, I want all of you to write more questions because I'm seriously not a specialist in this.And please, no snardy remarks in the style of "Microevolution is a term used by creos to escape admitting evolution, or macroevolution happens".

Reasonable topic. Promoted to Biological Evolution.

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